Isolator

ABSTRACT

An isolator includes a work chamber, a sterilizing substance supply unit, a gas flow channel pressure adjustment unit, a work chamber barometer, and a controller. The controller is configured to control execution of a gas flow channel leak test for checking a gas leak in a gas flow channel based on a detection result by the work chamber barometer after making the gas flow channel pressure adjustment unit increase or decrease the pressure in the gas flow channel, and is configured to control supply of the sterilizing substance by the sterilizing substance supply unit. The controller performs heating of a heater, which accompanies the supply of the sterilizing substance, in parallel with the gas flow channel leak test.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 12/863,080filed on Jul. 15, 2010, which is a National Stage of PCT/JP2009/003981,filed on Aug. 20, 2009 and claims the benefit thereof, which is basedupon and claims the benefit of priority of Japanese Patent ApplicationNo. 2008-212233 filed on Aug. 20, 2008 and Japanese Patent ApplicationNo. 2008-243258 filed on Sep. 22, 2008. The entire contents of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an isolator.

DESCRIPTION OF THE RELATED ART

An isolator includes therein a work chamber that is under a sterileenvironment and is used for the work that is performed in a sterileenvironment in the work chamber, for example, for a work in which abiomaterial is handled, such as cell culture. Herein, the sterileenvironment means an environment that is as close to a dust-free,sterile environment as possible to prevent contamination of substancesother than ones necessary for the work to be performed in the workchamber.

In an isolator, to maintain the sterile environment in the work chamber,a sterilizing process is performed in which a sterilizing substance,such as hydrogen peroxide, is supplied into the work chamber such thatthe inside of the work chamber is sterilized (see Japanese PatentApplication Publications Nos. 2006-68122 and 2005-218548). In theisolator system described in Japanese Patent Application Publication No.2006-68122, liquid hydrogen peroxide is vaporized by being hit withdried, hot air and the resultant hydrogen peroxide gas is supplied intothe isolator. In the decontamination apparatus described in JapanesePatent Application Publication No. 2005-218548, hydrogen peroxidesolution is vaporized by a heater and the resultant hydrogen peroxidegas is supplied into the isolator.

If a large amount of a sterilizing substance leaks out from thesterilized space, including a work chamber, during a sterilizingprocess, the concentration of the sterilizing substance is decreased,thereby possibly leading to insufficient sterilization. In addition,because a sterilizing substance, such as hydrogen peroxide, is harmfulto human bodies, it is desirable that the sterilizing substance does notleak out from an isolator. Accordingly, in the decontamination apparatusdescribed in Japanese Patent Application Publication No. 2005-218548, aleak test of the isolator is performed prior to the supply of thesterilizing substance.

Also, in an isolator, the air that has been taken in from a gas supplyunit is supplied into the work chamber through a particulate trapfilter, such as HEPA filter (High Efficiency Particulate Air filter),which is provided between a gas supply unit and the work chamber, inorder to secure the sterile environment in the work chamber. The air inthe work chamber is discharged from a gas discharge unit through aparticulate trap filter, which is provided between the work chamber andthe gas discharge unit.

In addition, prior to the start of the subsequent work after a work iscompleted in the work chamber, the work chamber is sterilized byspraying therein, for example, hydrogen peroxide as a sterilizingsubstance from a sterilizing substance supply unit (see Japanese PatentApplication Publication No. 2005-312799).

As a method for measuring the concentration of a sterilizing substancein an isolator, a system is known in which the concentration thereof ina sterilized chamber is measured in real time. This system is intendedto check whether the transitional gas concentration satisfies thecondition under which the sterilization is achieved (see Japanese PatentApplication Publication No. 2008-68088). Another system is also known inwhich the temperature and humidity are measured in each of the gas flowupstream and the gas flow downstream of a hydrogen peroxide gasgenerator, the hydrogen peroxide gas being a sterilizing gas. Thissystem is intended to determine the concentration of the hydrogenperoxide gas to be supplied into a sterilized chamber (see JapanesePatent Application Publication No. 2007-202628).

-   [Patent Document 1] Japanese Patent Application Publication No.    2006-68122-   [Patent Document 2] Japanese Patent Application Publication No.    2005-218548-   [Patent Document 3] Japanese Patent Application Publication No.    2005-312799-   [Patent Document 4] Japanese Patent Application Publication No.    2008-68088-   [Patent Document 5] Japanese Patent Application Publication No.    2007-202628

SUMMARY OF THE INVENTION

In the aforementioned circumstances, the present inventors haverecognized the following challenges. In the structures described in theaforementioned Patent Documents 1 and 2, it is needed to start thegeneration of the hydrogen peroxide gas after the temperature of theheater, which is used for heating dried air or hydrogen peroxidesolution itself, is heated to the desired temperature in order to stablygenerate hydrogen peroxide gas of a uniform concentration.

On the other hand, if heating of the heater is started during a leaktest of an isolator, the pressure in the isolator varies due to the heatfrom the heater. Further, the pressure in the isolator varies due to thevariation in the pressure in the space near the heater due to the heatfrom the heater. Therefore, a leak test with high reliability cannot beperformed. Accordingly, it is needed to perform, at first, a leak testof an isolator, then to start the heating of a heater after the leaktest is completed, and then to perform a sterilizing process bygenerating hydrogen peroxide gas after the heater has reached thedesired temperature.

In an isolator, if a sterilizing process takes a long time, it alsotakes a long time before the isolator is in a state where the subsequentwork can be started, thereby deteriorating the work efficiency.Accordingly, it is demanded that the time necessary for a sterilizingprocess be shortened in order to improve the work efficiency in anisolator. In the structures described in Patent Documents 1 and 2, thepre-heating of the heater is started after a leak test is completed, andhence there is room for shortening the time necessary for a sterilizingprocess.

In a conventional substitution step for hydrogen peroxide gas, thedischarge amount of the gas is constant throughout the step withoutmeasuring the concentrations of the sterilizing substance during thedischarge. Accordingly, the discharge amount is not controlled inaccordance with the concentration of the sterilizing substance in thedischarge air. Therefore, when performing discharge at a large dischargeamount, a process for efficiently reducing the sterilizing substance isnot performed in the first half of a substitution step by the equipment(a reduction process unit) for reducing the concentration of thesterilizing substance in the discharge air. Accordingly, the non-reactedsterilizing substance is discharged into the air, thereby causing theproblem that workers, etc., may be exposed to danger. On the other hand,when performing discharge at a small discharge amount, there occurs theproblem that the discharge takes a too long time in the second half ofthe substitution step in which the concentration of the sterilizingsubstance in the isolator is decreased.

The present invention has been made based on such recognition by thepresent inventors, and a purpose of the invention is to provide atechnique in which the time necessary for a sterilizing process in anisolator can be further shortened.

Another embodiment of the present invention has been made in view ofthese situations, and another purpose thereof is to provide a techniquein which, when a sterilizing process is performed between the previouswork and the subsequent work in an isolator, the isolator is set to thestate in an earlier time where the subsequent work can be started, and atechnique in which discharge amount of a sterilizing substance into theair can be reduced.

An embodiment of the present invention is an isolator. The isolatorcomprises: a work chamber for performing a work in which a biomaterialis handled; a sterilizing substance supply unit that is provided in astate independent from a gas flow channel including the work chamber interms of heat and pressure, and that has a heater for heating asterilizing substance to be vaporized, and that is configured to supplythe vaporized sterilizing substance into the gas flow channel; a gasflow channel pressure adjustment unit configured to increase or decreasethe pressure in the gas flow channel; a gas flow channel pressuredetector configured to detect the pressure inside the gas flow channel;and a controller configured to control execution of a gas flow channelleak test for checking a gas leak in the gas flow channel based on adetection result by the gas flow channel pressure detector after makingthe gas flow channel pressure adjustment unit increase or decrease thepressure in the gas flow channel, and configured to control supply ofthe sterilizing substance by the sterilizing substance supply unit, inwhich the controller performs heating of a heater, which accompanies thesupply of the sterilizing substance, in parallel with the gas flowchannel leak test.

According to this embodiment, the time necessary for a sterilizingprocess in an isolator can be further shortened.

In the aforementioned embodiment, the isolator may comprise: a supplyunit pressure adjustment unit configured to increase or decrease thepressure in the sterilizing substance supply unit; and a supply unitpressure detector configured to detect the pressure in the sterilizingsubstance supply unit, in which the controller makes the supply unitpressure adjustment unit increase or decrease the pressure in thesterilizing substance supply unit when the heater is at normaltemperature, and in which the controller controls execution of a supplyunit leak test for checking a gas leak in the sterilizing substancesupply unit based on a detection result by the supply unit pressuredetector.

Another embodiment of the present invention is also an isolator. Theisolator comprises: a work chamber for performing a work in which abiomaterial is handled; a gas supply unit configured to supply a gasinto the work chamber; a gas discharge unit configured to discharge thegas from the work chamber; a connection channel that has a particulatetrap filter and connects the gas supply unit with the work chamber; asterilizing substance supply unit configured to supply a sterilizingsubstance into the work chamber; a discharge means configured to controlthe discharge amount of the gas that is discharged from the gasdischarge unit; a reduction process unit configured to reduce theconcentration of the sterilizing substance that is contained in the gasdischarged from the gas discharge unit; and a controller configured tostart discharge by using the discharge means after sterilizing theinside of the work chamber by supplying the sterilizing substance intothe work chamber to maintain the concentration of the sterilizingsubstance in the work chamber, and configured to make the dischargeamount at the end of the discharge larger than that occurring when theconcentration of the sterilizing substance reaches the maximum.

According to this embodiment, when performing a sterilizing processbetween the previous work and the subsequent work in an isolator, theisolator can be set to the state in an earlier time where the subsequentwork can be started by an efficient substitution step. Further, when thesterilizing substance in the discharge gas reaches a predeterminedconcentration, the discharge amount is suppressed, and hence it can besuppressed to the minimum that the sterilizing substance, which has notbeen treated by the sterilizing substance reduction process unit, may bedischarged into the air. As a result, the safety of a worker can beimproved.

In the aforementioned another embodiment, the isolator may furthercomprise a concentration measurement unit that is provided in the gasdischarge unit and configured to measure the concentration of thesterilizing substance remaining in the gas that is discharged from thegas discharge unit, in which the controller gradually increases thedischarge amount before the concentration, which has been measured bythe concentration measurement unit, reaches a predetermineddetermination concentration such that the discharge amount is maintainedwithin a predetermined range after the concentration has reached thedetermination concentration, and the controller further graduallyincreases the discharge amount on condition that a reduction rate of theconcentration, which has been measured by the concentration measurementunit, exceeds a predetermined threshold value.

Further, in the aforementioned another embodiment, the isolator mayfurther comprise a concentration measurement unit that is provided inthe gas discharge unit and configured to measure the concentration ofthe sterilizing substance remaining in the gas that is discharged fromthe gas discharge unit, in which the controller controls the dischargeamount by feedback using the concentration, which has been measured bythe concentration measurement unit, so that the discharge amount isgradually increased before the concentration reaches a predetermineddetermination concentration and that the concentration of thesterilizing substance in the discharge gas is within a predeterminedrange after the concentration has reached the determinationconcentration, and the controller fixes the discharge amount oncondition that the discharge amount has reached a predetermineddischarge amount.

Also, in the aforementioned another embodiment, when the concentrationmeasurement unit is provided on the gas flow downstream side of thereduction process unit, the isolator may further comprise anotherconcentration measurement unit, which is provided on the gas flowupstream side thereof, in which the controller measures, by using theanother measurement unit, the concentration of the sterilizing substancein the discharge gas before being subjected to the reduction process oncondition that the concentration of the sterilizing substance in thedischarge gas after being subjected to the reduction process has reachedthe detection limit of the concentration measurement unit, theconcentration being measured by the concentration measurement unit, andwherein the controller ends the discharge by the gas discharge unit oncondition that the concentration of the sterilizing substance, which hasbeen measured by the another concentration measurement unit, has reachedthe detection limit of the another concentration measurement unit.

In the aforementioned another embodiment, the isolator may comprise ameasurement unit configured to measure the time elapsed since thedischarge of the gas in the work chamber is started until theconcentration of the sterilizing substance reaches the detection limitof the concentration measurement unit, in which the controllercommunicates that the capability of the reduction process unit isdecreased when the measured time exceeds a predetermined thresholdvalue.

In the aforementioned another embodiment, the sterilizing substance maybe hydrogen peroxide.

Appropriate combinations of the aforementioned each component can beencompassed by the scope of the present invention seeking the protectionof the patent by the present patent application.

EFFECT OF THE INVENTION

According to the present invention, the time necessary for a sterilizingprocess in an isolator can be further shortened.

Also, according to the another embodiment of the present invention,discharge of a sterilizing substance into the air can be reduced as wellas the time necessary for a sterilizing process being shortened.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, byway of example only, with referenceto the accompanying drawings which are meant to be exemplary, notlimiting, and wherein like elements are numbered alike in severalFigures, in which:

FIG. 1 is a schematic view illustrating the structure of an isolatoraccording to Embodiment 1;

FIG. 2 is a schematic view illustrating the structure of a sterilizingsubstance supply unit;

FIG. 3 is a graph for explaining a leak test of the isolator;

FIG. 4 is a view illustrating the state of the isolator when asterilizing substance is supplied;

FIG. 5 is a graph explaining check timing of a gas leak in thesterilizing substance supply unit;

FIG. 6 is a schematic view illustrating the structure of an isolatoraccording to Embodiment 2;

FIG. 7 is a schematic view illustrating a sterilizing substance sendingunit;

FIG. 8 is a schematic graph illustrating discharge control according toEmbodiment 2;

FIG. 9 is a schematic graph illustrating capability determination of asterilizing substance reduction process unit according to Embodiment 2;

FIG. 10 is a schematic graph illustrating discharge control according toEmbodiment 3;

FIG. 11 is a schematic view illustrating the structure of an isolatoraccording to Embodiment 4;

FIG. 12 is a schematic graph illustrating discharge control according toEmbodiment 4; and

FIG. 13 is a schematic graph in which the detection limit region C ofthe concentration of the hydrogen peroxide gas in FIG. 12 is enlarged.

REFERENCE NUMERALS

-   10, 1010 WORK CHAMBER-   16 WORK CHAMBER THERMOMETER-   18 WORK CHAMBER BAROMETER-   20, 1040 GAS SUPPLY UNIT-   22, 1042 INTAKE VENT-   23 INTAKE VALVE-   24 INTAKE FAN-   26 PARTICULATE TRAP FILTER-   30, 1050 GAS DISCHARGE UNIT-   32, 1058 DISCHARGE VENT-   33 DISCHARGE VALVE-   34 DISCHARGE FAN-   36 PARTICULATE TRAP FILTER-   38 STERILIZING SUBSTANCE REMOVAL FILTER-   40, 1030 STERILIZING SUBSTANCE SUPPLY UNIT-   42, 1033, 1035 STERILIZING SUBSTANCE SUPPLY PIPE-   44 STERILIZING SUBSTANCE CIRCULATION CHANNEL-   50, 1090 CONTROLLER-   60 CIRCULATION VENT-   61 CIRCULATION CHANNEL VALVE-   100, 1100, 1300 ISOLATOR-   402 STERILIZING GAS GENERATOR-   410 ATOMIZING UNIT-   413 ULTRASONIC TRANSDUCER-   414 CUP-   419 SUPPLY UNIT BAROMETER-   420 VAPORIZATION UNIT-   421 HEATING PIPE-   422 HEATER-   423 FLOW CHANNEL FORMATION BOARD-   424 PIPE-   425 THERMOMETER-   427, 475 HEAT-INSULATING CONNECTION PORTION-   428, 474 VALVE-   460 HYDROGEN PEROXIDE SOLUTION CARTRIDGE-   462 PIPE-   464, 1034 PUMP-   470 AIR SUPPLY FAN-   1012 FRONT DOOR-   1014 WORK GLOVE-   1016 GAS SUPPLY VENT-   1018 GAS DISCHARGE VENT-   1020, 1022 HEPA FILTER-   1032 STERILIZING SUBSTANCE SUPPLY TANK-   1036 STERILIZING SUBSTANCE SENDING UNIT-   1044, 1052 THREE-WAY VALVE-   1046 FAN-   1054 STERILIZING SUBSTANCE REDUCTION PROCESS UNIT-   1056, 1060 CONCENTRATION MEASUREMENT UNIT-   1070, 1072, 1074, 1076, 1078, 1080, 1082 CHANNEL-   1092 MEASUREMENT UNIT-   1094 RECORDING UNIT-   1202 CONTROL SUBSTRATE-   1203 HYDROGEN PEROXIDE GAS (MIST)-   1204 HYDROGEN PEROXIDE SOLUTION TANK-   1206 WATER SEAL CAP

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention will be described with reference tothe drawings based on the preferred embodiments of the invention. Thesame or like components, members, or processes illustrated in eachdrawing are denoted by like reference numerals, and the duplicativedescriptions will be appropriately omitted. The embodiments are notintended to limit the invention but to serve as particular examplesthereof, and all features or combinations thereof described there arenot always essential to the present invention.

Embodiment 1

FIG. 1 is a schematic view illustrating the structure of an isolator 100according to Embodiment 1.

As illustrated in FIG. 1, the isolator 100 according to Embodiment 1comprises a work chamber 10, a gas supply unit 20, a gas discharge unit30, a sterilizing substance supply unit 40, and a controller 50.

The work chamber 10 is a space for performing a work in which abiomaterial is handled, such as cell extraction and cell culture. Afront door 12 is provided in the work chamber 10 in an openable andclosable manner, and work gloves 14 for performing a work within thework chamber 10 are provided at certain positions of the front door 12.A worker can perform, through the work gloves 14, a work within the workchamber 10 after inserting his/her hands from not-illustrated openingsthat are provided on the front door 12. Herein, the biomaterial means amaterial that includes a living organism itself including cells, asubstance of which a living organism is composed, or a substance that isproduced by a living organism. In addition, a work chamber thermometer16 for detecting the temperature inside the work chamber 10, and a workchamber barometer 18, as a gas flow channel pressure detector fordetecting the pressure inside the gas flow channel including the workchamber 10, are provided in the work chamber 10.

The gas supply unit 20 comprises an intake vent 22 and an intake fan 24,such as a Sirocco fan, and takes in the gas outside the isolator 100from the intake vent 22 by the intake fan 24 to supply the gas into theisolator 100. A particulate trap filter 26, such as HEPA (HighEfficiency Particulate Air) filter, is provided in the connectionportion in the gas supply unit 20, the connection portion beingconnected with the work chamber 10. An intake valve 23 is provided inthe intake vent 22 in an openable and closable manner, thereby intake ofthe outside air from the intake vent 22 being controlled by opening andclosing of the intake valve 23. In addition, a circulation vent 60 isprovided in the gas supply unit 20, and a circulation channel valve 61is provided in the circulation vent 60 in an openable and closablemanner.

The gas discharge unit 30 comprises a discharge vent 32 and a dischargefan 34, such as a Sirocco fan, and discharges, from the discharge vent32, the gas within the work chamber 10 to the outside of the isolator100. A particulate trap filter 36, such as HEPA filter, is provided onthe gas flow upstream side of the discharge fan 34 in the gas dischargeunit 30. A discharge valve 33 is provided in the discharge vent 32,thereby discharge of the gas from the discharge vent 32 being controlledby opening and closing of the discharge valve 33. In addition, asterilizing substance removal filter 38, which includes activated carbonand platinum catalyst, etc., is provided on the gas flow upstream sideof the discharge valve 33 in the discharge vent 32. In the isolator 100according to the present embodiment, a gas flow channel pressureadjustment unit, which is used for increasing or decreasing the pressurein the gas flow channel including the work chamber 10, is structuredwith the intake fan 24 and the discharge fan 34. Herein, the gas flowchannel including the work chamber 10 means the area from the intakevent 22 to the discharge vent 32, which include, for example, the gassupply unit 20 and the gas discharge unit 30.

The sterilizing substance supply unit 40 is used for supplying avaporized sterilizing substance into the inside of the gas flow channelincluding the work chamber 10. One end of the sterilizing substancesupply unit 40 is connected with the work chamber 10 through asterilizing substance supply pipe 42 and the other end thereof isconnected, through a sterilizing substance circulation channel 44, withthe gas flow channel between the work chamber 10 and the gas dischargeunit 30. A valve 428 is provided in the sterilizing substance supplypipe 42, and a valve 474 is provided in the sterilizing substancecirculation channel 44. In the isolator 100, the inside of the gas flowchannel including the work chamber 10 can be under a sterile environmentby supplying a sterilizing substance from the sterilizing substancesupply unit 40. Herein, the sterile environment means an environment asclose to the dust-free, sterile environment as possible in order toprevent contamination of a substance other than the substances that arenecessary for the work performed in the work chamber.

In the present embodiment, the sterilizing substance is hydrogenperoxide and the sterilizing substance supply unit 40 has, for example,the structure that is illustrated in FIG. 2. FIG. 2 is a schematic viewillustrating the structure of the sterilizing substance supply unit 40.

As illustrated in FIG. 2, the sterilizing substance supply unit 40 has asterilizing gas generator 402 that is composed of an atomizing unit 410and a vaporization unit 420, a hydrogen peroxide solution cartridge 460that stores a hydrogen peroxide solution, and an air supply fan 470 thatserves as a supply unit pressure adjustment unit.

The atomizing unit 410 has a housing member 411, a cover member 412, anultrasonic transducer 413, a cup 414, and a funnel member 415.

The ultrasonic transducer 413 is provided on the bottom surface of thehousing member 411. The ultrasonic transducer 413 is a device thattransforms electric energy into machinery vibrations of an ultrasonicrange. A supply unit barometer 419 is provided on the upper surface ofthe cover member 412 as a supply unit pressure detector that detects thepressure inside the sterilizing substance supply unit 40.

A flange 416 is formed on the upper outer circumference of the housingmember 411. In addition, a flange 417 is formed, corresponding to theflange 416, on the lower outer circumference of the cover member 412.The gap between the flanges 416 and 417 is sealed by fastening theflanges 416 and 417 with fastening members 418, such as screws, so thata space is formed inside the housing member 411 and the cover member412.

The internal space of the housing member 411 and the cover member 412 ispartitioned into an upper space 432 and a lower space 434 by the cup414. Specifically, the periphery of the cup 414 is inserted between theflanges 416 and 417 so as to be fixed by fastening the flanges 416 and417 with the fastening members 418.

Ultrasonic wave propagation liquid 440, which propagates machineryvibrations of an ultrasonic range generated by the ultrasonic transducer413, is filled in the lower space 434. As the ultrasonic wavepropagation liquid 440, liquid with a low viscosity, such as water, ispreferred. On the other hand, a funnel member 415, which is formed of apipe 480 and a funnel-shaped portion 482, is provided in the upper space432. The funnel member 415 will be described later.

Openings 450 and 452 are provided on the side surface of the covermember 412. In addition, an opening 454 is provided on the upper surfaceof the cover member 412. A pipe 462, which is used for supplying, intothe space 432, the hydrogen peroxide solution that is stored in thehydrogen peroxide solution cartridge 460, is inserted into the opening450. A pump 464, which is used for pumping the hydrogen peroxidesolution that is stored in the hydrogen peroxide solution cartridge 460,is provided in the middle of the pipe 462. As the pump 464, a pump, suchas a Peristalic pump, is preferred, by which the channel inside the pipe462 is shielded in an airtight manner such that the inside of thesterilizing substance supply unit can be maintained in an airtightmanner during a leak test of the supply unit, which will be describedlater. When the pump 464 has a structure in which the channel inside thepipe 462 is not shielded in an airtight manner, the channel thereof maybe shielded in an airtight manner by, for example, providing a shieldmeans, such as a valve, at a position of the pipe 462 between the pump464 and the hydrogen peroxide solution cartridge 460.

In addition, a pipe 472 for sending, into the space 432, the air sentfrom an air supply fan 470, such as an axial fan, which is provided inthe middle of the pipe 472, is connected with the opening 452. The otherend of the pipe 472, opposite to the opening 452, is connected with thesterilizing substance circulation channel 44 through a heat-insulatingconnection portion 475, which is made from a heat-insulating resin, etc.A valve 474 is provided in the end area on the heat-insulatingconnection portion 475 side of the sterilizing substance circulationchannel 44. Accordingly, the sterilizing substance circulation channel44 side of the sterilizing substance supply unit 40 is provided, by theheat-insulating connection portion 475 and the valve 474, in a stateindependent from the gas flow channel including the work chamber 10 interms of heat and pressure. The air supply fan 470 also serves as asupply unit pressure adjustment unit that increases the pressure in thesterilizing substance supply unit 40 by sending air into the space 432with positive rotation and that decreases the pressure therein bysucking in the air from the space 432 with negative rotation. The airsupply fan 470 is used for supplying the sterilizing substance into thework chamber 10.

The pipe 480 of the funnel member 415 is inserted into the opening 454and the funnel member 415 is fixed such that an opening 484 of thefunnel-shaped portion 482 is directed downwards. The other end of thepipe 480 is fixed to the vaporization unit 420. The opening 452 isprovided at a position higher than that of the opening 484 of thefunnel-shaped portion 482. Thereby, it is designed that the air sentfrom the opening 452 flows downwards along the outside of thefunnel-shaped portion 482 without directly blowing into the opening 484,and after turning back at the lower position of the funnel-shapedportion 482, the air flows upwards along the inside of the funnel-shapedportion 482.

In the atomizing unit 410 structured as stated above, the hydrogenperoxide solution, which has been supplied into the cup 414, is atomizedby the machinery vibrations of an ultrasonic range, and the atomizedhydrogen peroxide is sent, by the air sent from the air supply fan 470,into the vaporization unit 420 through the opening 484 of thefunnel-shaped portion 482 and the pipe 480. Because the funnel member415 is provided in the connection portion between the space 432 and thevaporization unit 420 and the opening 484 is funnel-shaped, the atomizedhydrogen peroxide is efficiently trapped to be sent into thevaporization unit 420. In this case, the hydrogen peroxide with arelatively large particle shape, which is adhering to the inside of thefunnel-shaped portion 482 without being atomized, falls on the cup 414due to gravity to be atomized again.

The vaporization unit 420 has a heating pipe 421, a heater 422, a flowchannel formation board 423, a pipe 424, and a thermometer 425.

The heating pipe 421 is connected with the pipe 480 such that the axialdirection thereof is directed vertically. A flow channel 426 is formedinside the heating pipe 421, through which the hydrogen peroxide and theair, which have been sent from the pipe 480, flow from downward toupward. The flow channel formation boards 423, which protrude from theinside of the heating pipe 421 in the direction perpendicular to theaxis of the heating pipe 421, are alternately provided inside theheating pipe 421. Thereby, the flow channel 426, which is providedinside the heating pipe 421, meanders and becomes long. As a result, thehydrogen peroxide remains in the flow channel 426 for a longer time,thereby ensuring that the hydrogen peroxide is gasified within the flowchannel 426.

In the present embodiment, the heating pipe 421 is provided immediatelyabove the space 432. Accordingly, when the hydrogen peroxide isliquefied within the heating pipe 421 without being gasified, theliquefied hydrogen peroxide falls into the space 432 due to gravity. Thehydrogen peroxide, which has returned into the space 432, is againatomized by the machinery vibrations of a ultrasonic range to be sentinto the heating pipe 421. Thereby, the hydrogen peroxide within the cup414 can be surely gasified without waste by returning, with a simplifiedstructure, the hydrogen peroxide that has been liquefied within theheating pipe 421 so as to be atomized again.

The heater 422 for heating the atomized hydrogen peroxide to bevaporized is provided at the center portion of the heating pipe 421 andalong the axis of the heating pipe 421. The heater 422 can be heated,for example, up to 150° C. that is appropriate for the vaporization ofthe hydrogen peroxide, and the temperature thereof is adjusted withon/off control by the controller 50. It is desirable that a plurality offins are provided in the heater 422. Thereby, the contact area betweenthe heater 422 and the hydrogen peroxide, flowing through the flowchannel 426, can be increased such that the gasification of the hydrogenperoxide is promoted.

One end of the pipe 424 is connected with the upper side surface of theheating pipe 421. A thermometer 425 for measuring the internaltemperature of the pipe 424 is provided in the pipe 424. The other endof the pipe 424 is connected with the sterilizing substance supply pipe42 through a heat-insulating connection portion 427, which is made froma heat-insulating resin, etc. A valve 428 is provided in the end area onthe heat-insulating connection portion 427 side of the sterilizingsubstance supply pipe 42. Accordingly, the sterilizing substance supplypipe 42 side of the sterilizing substance supply unit 40 is provided, bythe heat-insulating connection portion 427 and the valve 428, in a stateindependent from the flow channel including the work chamber 10 in termsof heat and pressure.

In the sterilizing substance supply unit 40 structured as stated above,the operations for supplying a sterilizing gas will be described.

The heater 422 is at first switched on such that heating of the heater422 is started and the pump 464 is driven such that the hydrogenperoxide stored in the hydrogen peroxide solution cartridge 460 ispumped up, thereby sending the hydrogen peroxide toward the space 432.

The internal temperature of the pipe 424 starts to rise from normaltemperature by switching on the heater 422. Further, when the hydrogenperoxide solution reaches the space 432 through the pipe 462, thehydrogen peroxide solution starts to accumulate on the bottom of the cup414, and the amount of the sterilizing substance solution within the cup414 starts to rise.

When the thermometer 425 for measuring the internal temperature withinthe pipe 424 reaches the temperature at which the hydrogen peroxide gasis not recondensed, for example 90° C., the ultrasonic transducer 413 isdriven such that machinery vibrations of an ultrasonic range arepropagated into the space 432 through the ultrasonic wave propagationliquid 440. In addition, air blasting is started by the air supply fan470 such that the air within the gas flow channel is sent into the space432 through the sterilizing substance circulation channel 44. Thereby,the hydrogen peroxide is atomized in the space 432, and the atomizedhydrogen peroxide is supplied into the heating pipe 421 by the air blastfrom the air supply fan 470. The atomized hydrogen peroxide, which hasbeen supplied into the heating pipe 421, is gasified by heating with theheater 422. The gasified hydrogen peroxide is supplied into thesterilizing substance supply pipe 42 through the pipe 424.

It is desirable that the flow amount of the hydrogen peroxide solution,which is to be sent toward the space 432 by the pump 464, is controlledsuch that the amount of the hydrogen peroxide solution in the cup 414 isappropriate for being atomized by the machinery vibrations of aultrasonic range. Thereby, the hydrogen peroxide solution in the cup 414can be efficiently atomized.

When the hydrogen peroxide solution does not remain in the hydrogenperoxide solution cartridge 460 by being gradually consumed, the supplyof the hydrogen peroxide solution into the space 432 is stopped. Afterthe supply of the hydrogen peroxide solution into the upper space 432 isstopped, the amount of the hydrogen peroxide solution in the cup 414 isgradually decreased, and finally the residue of the hydrogen peroxidesolution in the cup 414 becomes zero.

When the residue of the hydrogen peroxide solution in the cup 414becomes zero, the amount of the atomized hydrogen peroxide, which is tobe sent from the atomizing unit 410 to the vaporization unit 420, isgradually decreased, and hence the heat amount, which is consumed by thevaporization of the hydrogen peroxide, is gradually decreased. Thereby,the internal temperature within the pipe 424 further rises from thevaporization temperature of the hydrogen peroxide.

When the internal temperature within the pipe 424, which has beenmeasured by the thermometer 425, has reached a predetermineddetermination temperature, the heater 422 is switched off such that theheating of the heater 422 is stopped. The determination temperaturemeans the internal temperature within the pipe 424 at which only the airstarts moving through the heating pipe 421 after the gasification of thehydrogen peroxide within the heating pipe 421 has been completed. Thatis, the fact that the internal temperature within the pipe 424 reaches apredetermined determination temperature means that the residue of thehydrogen peroxide solution in the cup 414 becomes zero and the hydrogenperoxide solution to be gasified no longer remains in the sterilizingsubstance supply unit 40. After the heater 422 is turned off, theinternal temperature within the pipe 424 gradually falls and thenreturns to normal temperature.

The structure of the sterilizing substance supply unit 40 shall not belimited to the aforementioned one, but may be one in which hydrogenperoxide gas is generated by, for example, supplying the hydrogenperoxide solution into a heated container to be vaporized. In addition,a sterilizing substance shall not be limited to hydrogen peroxide, butmay be a substance containing, for example, an active oxygen species,such as ozone.

The controller 50 controls: opening/closing of the intake valve 23, thedischarge valve 33, and the circulation channel valve 61; on/off of theintake fan 24 and the discharge fan 34; drive of the pump 464 in thesterilizing substance supply unit 40; opening/closing of the valves 428and 474; and on/off of the heater 422, the air supply fan 470, and theultrasonic transducer 413.

Subsequently, the sterilizing process in the isolator 100, which isstructured as stated above, will be described. FIG. 3 is a graph forexplaining a leak test of the isolator 100. FIG. 4 is a viewillustrating the state of the isolator 100 when a sterilizing substanceis supplied.

In the state where a work is being performed in the work chamber 10, thecontroller 50 controls the intake valve 23 and the discharge valve 33 soas to be in open states, and controls the circulation channel valve 61so as to be in a closed state, as illustrated in FIG. 1. Further, thecontroller 50 makes the intake fan 24 and the discharge fan 34 drive.Thereby, as illustrated by the arrows in FIG. 1, a gas flow channel isformed in the isolator 100 in which the open air is supplied into thework chamber 10 from the intake vent 22 and the gas in the work chamber10 is discharged outside the isolator 100 from the discharge vent 32.

In the isolator 100, before the start of the first work, after the endof a work (previous work) within the work chamber 10, and before thestart of the subsequent work, a sterilizing process for sterilizing theinside of the gas flow channels including the work chamber 10 isperformed. The sterilizing process in the isolator 100 includes apretreatment step, a sterilizing step, and a removal step.

In the pretreatment step, a gas flow channel leak test is performedunder the control of the controller 50, in which a gas leak in the gasflow channel including the work chamber 10, which is to be filled withhydrogen peroxide gas, is checked. Hereinafter, the gas flow channelleak test will be described with reference to FIG. 3.

In the gas flow channel leak test, the intake fan 24 is turned on in thestate where the intake valve 23 is in an open state and the dischargevalve 33 is in a closed state, thereby the open air being taken into theinside of the gas flow channel in the isolator 100. At the time, thevalves 428 and 474 are set to closed states. Thereby, the pressurewithin the gas flow channel is increased. The pressure in the gas flowchannel is almost the same as that in the work chamber 10, which can bedetected by the work chamber barometer 18. The controller 50 detects,from a detection result by the work chamber barometer 18, that thepressure in the gas flow channel has reached the test pressure, which isnecessary for the leak test. When the pressure in the gas flow channelreaches the test pressure, the controller 50 closes the intake valve 23and turns off the intake fan 24. Alternatively, it may be designed thatthe gas flow channel has a negative pressure by driving the dischargefan 34 in the state where the intake valve 23 is in a closed state andthe discharge valve 33 is in an open state.

Subsequently, the state of the isolator 100 is maintained as it is for acertain period, for example, 10 minutes. After the certain period haspassed, the controller 50 determines whether a leak occurs based on adetection result by the work chamber barometer 18. When the pressure inthe gas flow channel after the certain period exceeds the acceptablepressure decrease c (curve a), the controller 50 continues thesterilizing process. On the other hand, when the pressure in the gasflow channel after the certain period is below the acceptable pressuredecrease c (curve b), the controller 50 discontinues the sterilizingprocess and communicates the discontinuation of the sterilizing processto a worker by presenting that a gas leak has occurred with anon-illustrated information unit. With the aforementioned procedures,the gas flow channel leak test is completed.

Also, in the pretreatment step, the heater 422 is switched on such thatheating of the heater 422 is started. In a conventional isolator, anaccurate gas flow channel leak test cannot be performed because: whenheating of the heater 422 is started during the gas flow channel leaktest, the pressure in the gas flow channel varies due to the heat fromthe heater 422; and the pressure in the gas flow channel further variesdue to the variation in the pressure within the sterilizing substancesupply unit 40 due to the heat from the heater 422. Accordingly, it isneeded to start heating of the heater 422 after the gas flow channelleak test is completed. On the other hand, in the isolator 100 accordingto the present embodiment, the gas flow channel and the sterilizingsubstance supply unit 40, including the heater 422, are connected,through the heat-insulating connection portions 427 and 475 and thevalves 428 and 474, in a state independent from each other in terms ofheat and pressure. Therefore, heating of the heater 422 can be startedduring the gas flow channel leak test.

As illustrated in FIG. 4, when the temperature of the heater 422 hasreached a predetermined temperature, the intake valve 23 and thedischarge valve 33 are set to closed states, the circulation channelvalve 61 is set to an open state, and the intake fan 24 is turned on.And also, the valves 428 and 474 are set to open states such thatgeneration of the hydrogen peroxide gas is started. The generatedhydrogen peroxide gas is supplied into the work chamber 10 through thesterilizing substance supply pipe 42 and circulates within the gas flowchannel as illustrated by the arrows in FIG. 4. Herein, thepredetermined temperature means the internal temperature within the pipe424 at which the hydrogen peroxide gas is not recondensed.

When the hydrogen peroxide gas is supplied into the gas flow channel andthe concentration of the hydrogen peroxide gas within the gas flowchannel, including the work chamber 10, is greater than or equal to theconcentration that is necessary for the sterilizing process, thesterilizing step is started. As illustrated in FIG. 4, in thesterilizing step, the hydrogen peroxide gas, which has been sent fromthe sterilizing substance supply unit 40, circulates along the route ofthe work chamber 10, the circulation vent 60, the discharge fan 34, andthe work chamber 10 such that these areas are sterilized, in the statewhere the intake valve 23 and the discharge valve 33 are set to closedstates and the circulation channel valve 61 is set to an open state. Thesterilizing process enters the removal step after the sterilizing stepis completed.

In the removal step, the supply of the hydrogen peroxide gas from thesterilizing substance supply unit 40 is stopped, and the intake valve 23and the discharge valve 33 are set to open states, the circulationchannel valve 61 is set to a closed state, and the intake fan 24 and thedischarge fan 34 are turned on. Thereby, air outside the isolator 100 istaken in from the intake vent 22 to be supplied into the gas flowchannel. And also, the hydrogen peroxide gas within the gas flow channelis sent into the gas discharge unit 30 to be removed by being adsorbedwith the sterilizing substance removal filter 38 or by being degraded.

When air is substituted for the gas in the gas flow channel and theconcentration of the hydrogen peroxide gas in the gas flow channelbecomes smaller than or equal to a predetermined concentration in theremoval step, the work chamber is in the state of being able to be usedand the sterilizing process is completed. Herein, the concentration ofthe hydrogen peroxide gas at which the work chamber 10 is in the stateof being able to be used means the concentration at which thebiomaterial, which is used in a work, is not affected to the extent thatcannot be neglected for the work. The concentration is, for example,smaller than or equal to 1 ppm (TWA: Time Weighted Average) that isspecified by ACGIH (American Conference of Government IndustrialHygienists).

Herein, a collective leak test can be performed by executing the samesteps as in the aforementioned gas flow channel leak test with thevalves 428 and 474 being set to open states, in which a gas leak in thetotal space of the gas flow channel and the sterilizing substance supplyunit 40 can be checked. Alternatively, the collective leak test may beperformed by executing the same steps as in a supply unit leak test,which will be described later, with the valves 428 and 474 being set toopen states.

Subsequently, the supply unit leak test will be described. In theisolator 100 according to the present embodiment, a supply unit leaktest is performed in addition to the gas flow channel leak test and thecollective leak test, in which a gas leak in the sterilizing substancesupply unit 40 is checked independently from the gas leak in the gasflow channel. In the isolator 100 according to the embodiment, thesterilizing substance supply unit 40 is provided with the air supply fan470 and the supply unit barometer 419, and the gas flow channel,including the work chamber 10, and the sterilizing substance supply unit40 are, by the valves 428 and 474, independent from each other in termsof pressure. Therefore, the supply unit leak test can be performedindependently from the gas flow channel leak test.

In the supply unit leak test, the valve 428 is set to a closed state,the valve 474 is set to an open state, and the air supply fan 470 isturned on, so that air is taken into the sterilizing substance supplyunit 40. The air tightness of the pipe 462 is maintained by the pump 464or the aforementioned shield means. Thereby, the pressure in thesterilizing substance supply unit 40 is increased. The pressure in thesterilizing substance supply unit 40 is detected by the supply unitbarometer 419. The controller 50 detects, from a detection result by thesupply unit barometer 419, that the pressure in the sterilizingsubstance supply unit 40 has reached the test pressure, which isnecessary for the leak test. When the pressure in the sterilizingsubstance supply unit 40 has reached the test pressure, the controller50 closes the valve 474 and turns off the air supply fan 470.Alternatively, it may be designed that the sterilizing substance supplyunit 40 has a negative pressure by driving the air supply fan 470 in thestate where the valves 428 and 474 are set to open states.

Subsequently, the state of the sterilizing substance supply unit 40 ismaintained as it is for a certain period, for example, 10 minutes. Afterthe certain period has passed, the controller 50 determines, in the sameway as in the gas flow channel leak test, whether a leak occurs based ona detection result by the supply unit barometer 419. When the pressurein the sterilizing substance supply unit 40 after the certain periodexceeds the acceptable pressure decrease, the controller 50 continuesthe process to be subsequently performed. In contrast, when the pressureis below the acceptable pressure decrease, the controller 50communicates to a worker.

A gas leak in the sterilizing substance supply unit 40 is checked by thecollective leak test or the supply unit leak test, for example, at thefollowing timing. FIG. 5 is a graph explaining the check timing of a gasleak in the sterilizing substance supply unit 40.

Because the gas flow channel including the work chamber 10 has aportion, the sealing of which is secured by a manual operation, such asthe front door 12, it is desirable that a gas flow channel leak test isperformed at every sterilizing process. On the other hand, the gas leakin the sterilizing substance supply unit 40, which does not satisfy thestandard of the supply unit leak test, may occur only due to the agingdegradation of the non-illustrated packing, which are provided, forexample, in the openings 450, 452, and 454, etc. Therefore, the safetyof the isolator 100 can be secured even when the gas leak check of thesterilizing substance supply unit 40 is not performed so often as thegas flow channel leak test.

Accordingly, in the isolator 100 according to the present embodiment, itis designed that the gas leak check of the sterilizing substance supplyunit 40 is periodically performed while the heater 422 is being atnormal temperature, as illustrated in FIG. 5. That is, it is designedthat, of the works in a day, the collective leak test is performedbefore the first work is started (during the timing I in FIG. 5), andonly the leak test of the work chamber is performed when a work ischanged to another (during the timing II and III in FIG. 5).Alternatively, during the timing I in FIG. 5, the gas flow channel leaktest and the supply unit leak test may be performed in parallel witheach other instead of the collective leak test.

In the case where the gas leak check in the gas flow channel and that inthe sterilizing substance supply unit 40 are performed in this way,heating of the heater 422 can be started in parallel with the gas flowchannel leak test when the gas leak check in the sterilizing substancesupply unit 40 is not performed, by reducing the number of the gas leakchecks in the sterilizing substance supply unit 40. Therefore, the timenecessary for the sterilizing process can be shortened. Alternatively,it may be designed that only the supply unit leak test is performed, forexample, during the maintenance of the isolator 100. As stated above,the supply unit leak test can be set freely by providing the sterilizingsubstance supply unit 40 independently from the gas flow channel interms of heat and pressure.

Collectively describing operational effects by the aforementionedstructure, the isolator 100 according to the present embodimentcomprises the sterilizing substance supply unit 40 that is providedindependently from the gas flow channel, including the work chamber 10,in terms of heat and pressure, and heating of the heater 422 isperformed in parallel with the gas flow channel leak test. Accordingly,the time necessary for the sterilizing process in the isolator 100 canbe further shortened. As a result, the use efficiency of the isolator100 is improved, thereby allowing for the production amount of a treatedmaterial to be increased.

In the isolator 100, the sterilizing substance supply unit 40 comprisesthe air supply fan 470 and the supply unit barometer 419, and isprovided, by the valves 428 and 474, independently from the gas flowchannel in terms of pressure. Accordingly, the supply unit leak test forchecking a gas leak in the sterilizing substance supply unit 40 can beperformed independently from the gas flow channel leak test. Thereby,the degree of freedom in setting the supply unit leak test is increased,and hence the usability of the isolator 100 can be further improved.Moreover, because the site where a gas leak has occurred can be easilyspecified by performing the supply unit leak test and the gas flowchannel leak test independently from each other, the usability of theisolator 100 can be further improved.

Embodiment 2

FIG. 6 is a schematic view illustrating the structure of an isolator1100 according to Embodiment 2. The isolator 1100 according toEmbodiment 1 comprises: a work chamber 1010 for performing a work inwhich a biomaterial is handled, such as cell extraction and cellculture; a gas supply unit 1040 configured to supply a gas into the workchamber 1010; a gas discharge unit configured to discharge the gas inthe isolator 1100; a sterilizing substance supply unit 1030 configuredto supply a sterilizing substance into the work chamber 1010; and acontroller 1090 configured to control these operations. Herein, thebiomaterial means a material that includes a living organism itselfincluding cells, a substance of which a living organism is composed, ora substance that is produced by a living organism.

The gas supply unit 1040 is provided with an intake vent 1042, athree-way valve 1044, and a fan 1046. The open air is taken in throughthe intake vent 1042. The three-way valve 1044 is connected with the gasflow downstream side of the intake vent 1042 through a channel 1070 andconnected with the gas flow downstream side of a sterilizing substancesending unit 1036 through a channel 1080. Further, the three-way valve1044 is connected with the gas flow upstream side of the fan 1046through a channel 1072. In the three-way valve 1044, the gas flowchannel can be exclusively switched from the channel 1070 to thedirection of the channel 1072 or from the channel 1080 to that ofchannel 1072. The air that is taken in through the intake vent 1042, orthe gas that is sent through the channel 1080, which includes asterilizing substance, is taken in by the fan 1046 through the three-wayvalve 1044.

The fan 1046 sends the gas, which has been taken in from the directionof the three-way valve 1044 through the channel 1072, in the directionof the work chamber 1010 through the channel 1074. ON/OFF switching ofthe fan 1046 can be controlled by the controller 1090. The dischargeamount of the fan 1046 can be continuously controlled.

A front door 1012 is provided in the work chamber 1010 in an openableand closable manner, and work gloves 1014 for performing a work withinthe work chamber 1010 are provided at certain positions of the frontdoor 1012. A worker can perform, through the work gloves 1014, a workwithin the work chamber 1010 after inserting his/her hands fromnot-illustrated openings that are provided on the front door 1012. Thegas that has been sent by the fan 1046 is taken into the work chamber1010 from the gas supply vent 1016 and the gas is discharged from a gasdischarge vent 1018. HEPA filters 1020 and 1022 are provided in the gassupply vent 1016 and the gas discharge vent 1018, respectively. Withthese, the sterile state in the work chamber 1010 can be secured. Thegas, which has been discharged from the work chamber 1010, is sent intoa gas discharge unit 1050 through the gas discharge vent 1018, the HEPAfilter 1022, and a channel 1076.

The gas discharge unit 1050 is provided with a three-way valve 1052, asterilizing substance reduction process unit 1054, a concentrationmeasurement unit 1056, and a discharge vent 1058 in this order accordingto the gas flow.

The three-way valve 1052 is connected with the gas flow downstream sideof the work chamber 1010 through the channel 1076 and connected with thegas flow upstream side of the sterilizing substance reduction processunit 1054 through a channel 1082. Further, the three-way valve 1052 isconnected with the gas flow upstream side of the sterilizing substancesending unit 1036 through a channel 1078. In the three-way valve 1052,the gas flow channel can be exclusively switched from the channel 1076to the direction of the channel 1082 or from the channel 1076 to that ofthe channel 1078. The air, which has been taken in through the channel1076, is sent in the direction of the channel 1082 or the channel 1078.

The sterilizing substance reduction process unit 1054 performs areduction process for reducing the concentration of the sterilizingsubstance contained in the air, which has been sent through thethree-way valve 1052. The sterilizing substance reduction process unit1054 contains a metal catalyst, such as platinum, etc.; however, theprocess unit 1054 may contain activated carbon, etc.

The concentration measurement unit 1056 is provided in the gas flowdownstream of the sterilizing substance reduction process unit 1054 suchthat the concentration of the sterilizing substance in the dischargegas, after the reduction process has been performed, is measured. Ameasurement result is transmitted from the concentration measurementunit 1056 to the controller 1090. The gas, which has been subjected tothe reduction process by the sterilizing substance reduction processunit 1054, is discharged outside the isolator 1100 from the dischargevent 1058.

A sterilizing substance supply unit 1030 for supplying a sterilizingsubstance into the work chamber 1010 is provided outside the workchamber 1010. The sterilizing substance supply unit 1030 supplies asterilizing substance into the work chamber 1010 to circulate thesterilizing substance within the isolator 1100 and thereby the workchamber 1010 and the channels can be made in a sterile environment.Herein, the sterile environment means an environment that is as close toa dust-free, sterile environment as possible to prevent contamination ofsubstances other than ones necessary for the work to be performed in thework chamber. In the present embodiment, the sterilizing substance ishydrogen peroxide.

As illustrated in FIG. 6, the sterilizing substance supply unit 1030 islocated on the gas flow downstream side of the three-way valve 1052 andthe channel 1078, and located on the gas flow upstream side of thechannel 1080 and the three-way valve 1044. The sterilizing substancesupply unit 1030 has a sterilizing substance supply tank 1032, a pump1034, and a sterilizing substance sending unit 1036. The sterilizingsubstance supply tank 1032 stores hydrogen peroxide solution as asterilizing substance. The pump 1034 pumps the hydrogen peroxidesolution, which is stored in the sterilizing substance supply tank 1032,through a sterilizing substance supply pipe 1033 and sends the hydrogenperoxide solution through a sterilizing substance supply pipe 1035. Thesterilizing substance sending unit 1036 is connected with each of thegas flow downstream side of the three-way valve 1052 through the channel1078 and the gas flow upstream side of the three-way valve 1044 throughthe channel 1080. The sterilizing substance sending unit 1036 generateshydrogen peroxide gas or mist from the supplied hydrogen peroxidesolution. The generated hydrogen peroxide gas or mist is sent into thechannel 1080.

FIG. 7 is a schematic view illustrating the sterilizing substancesending unit 1036. The specific structure of the sterilizing substancesending unit 1036 will be described with reference to the drawing. Thesterilizing substance sending unit 1036 has a control substrate 1202, ahydrogen peroxide solution tank 1204, a water seal cap 1206, a hydrogenperoxide solution tub 1208, and an ultrasonic oscillator 1210.

The control substrate 1202 is a substrate for controlling the pump 1034.The hydrogen peroxide solution tank 1204 is a container for temporarilystoring the hydrogen peroxide solution. The water seal cap 1206 is a capfor controlling the supply amount of the hydrogen peroxide solution,which is sent from the hydrogen peroxide solution tank 1204 to thehydrogen peroxide solution tub 1208. The hydrogen peroxide solution tub1208, which is provided with the ultrasonic oscillator 1210 on itsbottom, is a water tub for temporarily storing the hydrogen peroxidesolution that has been sent from the hydrogen peroxide solution tank1204. The ultrasonic oscillator 1210 is an oscillator for generatinghydrogen peroxide gas or mist by ultrasonic oscillation. The hydrogenperoxide solution is housed in the sterilizing substance supply tank1032 illustrated in FIG. 6, which is supplied, by the pump 1034 beingcontrolled with, for example, the control substrate 1202, into thehydrogen peroxide solution tank 1204 from the sterilizing substancesupply tank 1032 through the sterilizing substance supply pipes 1033 and1035.

The hydrogen peroxide solution, which has been supplied into thehydrogen peroxide solution tank 1204, is supplied into the hydrogenperoxide solution tub 1208 through the water seal cap 1206 under thecontrol of the control substrate 1202. The hydrogen peroxide gas (mist)1203 is generated by providing ultrasonic oscillation using theultrasonic oscillator 1210 to the hydrogen peroxide solution in thehydrogen peroxide solution tub 1208. Although the generated hydrogenperoxide gas (mist) 1203 is sent toward the work chamber 1010 throughthe channel 1080, most of the hydrogen peroxide gas rapidly vaporizesand is present in the work chamber 1010 as hydrogen peroxide gas ormist. Hereinafter, it is sometimes referred to as hydrogen peroxide gasincluding hydrogen peroxide mist.

Without limiting to the structure in which the hydrogen peroxide gas ormist is generated as in the present embodiment, the sterilizingsubstance sending unit 1036 may be a hydrogen peroxide gas generator,etc., in which hydrogen peroxide gas or mist is generated by, forexample, hitting dropped hydrogen peroxide solution with air so as tovaporize the hydrogen peroxide solution. The sterilizing substance shallnot be limited to hydrogen peroxide, but may be a substance containing,for example, an active oxygen species, such as ozone.

Referring back to FIG. 6, the controller 1090 will be described. Thecontroller 1090 comprises a measurement unit 1092 and a recording unit1094. The controller 1090 controls sending of the sterilizing substanceby the sterilizing substance sending unit 1036. Further, the controller1090 controls switching of the gas flow channel by controllingopening/closing of the three-way valve 1044 and 1052.

Specifically, the controller 1090 controls exclusive switching of thegas flow channel from the channel 1070 to the direction of the channel1072 or from the channel 1080 to that of the channel 1072 by controllingopening/closing of the valve of the three-way valve 1044. Further, thecontroller 1090 controls exclusive switching of the gas flow channelfrom the channel 1076 to the direction of the channel 1082 or from thechannel 1076 to that of the channel 1078 by controlling opening/closingof the valve of the three-way valve 1052. Further, the controller 1090receives a measurement result from the concentration measurement unit1056 and controls, based on the received measurement result, therotational speed of the fan 1046 in accordance with a concentrationmeasurement result of the hydrogen peroxide gas in the discharge air bythe concentration measurement unit 1056, so that the discharge amount iscontinuously controlled. The measurement unit 1092 measures the timenecessary from the start to the end of the sterilizing process. Therecording unit 1094 records the measured time. The controller 1090determines whether the performance of the sterilizing substancereduction process unit 1054 is deteriorated by using the measurementunit 1092 and the recording unit 1094.

(Switching of Gas Flow Channel)

The gas flow channel of the isolator 1100 is switched in the followingtwo ways by the controller 1090 controlling opening/closing of thevalves of the three-way valves 1044 and 1052. That is, when making thehydrogen peroxide gas circulate within the isolator 1100, the three-wayvalve 1044 is set such that only the direction from the channel 1080toward the channel 1072 is in an open state and the direction from thechannel 1070 toward the channel 1072 is in a closed state. The three-wayvalve 1052 is set such that only the direction from the channel 1076toward the channel 1078 is in an open state and the direction from thechannel 1076 toward the channel 1082 is in a closed state. Thereby, acirculation channel is formed in which: the hydrogen peroxide gas entersthe work chamber 1010 from the sterilizing substance sending unit 1036through the channel 1080, the three-way valve 1044, the channel 1072,the fan 1046, the channel 1074, the HEPA filter 1020, and the gas supplyvent 1016; and returns to the sterilizing substance sending unit 1036through the gas discharge vent 1018, the HEPA filter 1022, the channel1076, the three-way valve 1052, and the channel 1078.

On the other hand, when substituting for the air in the work chamber,the three-way valve 1044 is set such that only the direction from thechannel 1070 toward the channel 1072 is in an open state and thedirection from the channel 1080 toward the channel 1072 is in a closedstate. The three-way valve 1052 is set such that only the direction fromthe channel 1076 toward the channel 1082 is in an open state and thedirection from the channel 1076 toward the channel 1078 is in a closedstate. Thereby, a channel is formed in which: air enters the workchamber 1010 from the intake vent 1042 through the channel 1070, thethree-way valve 1044, the channel 1072, the fan 1046, the channel 1074,the HEPA filter 1020, and the gas supply vent 1016; and the air isdischarged from the discharge vent 1058 through the gas discharge vent1018, the HEPA filter 1022, the channel 1076, the three-way valve 1052,the channel 1082, and the sterilizing substance reduction process unit1054.

(Sterilizing Process)

In the isolator 1100, between the end of a work (previous work) withinthe work chamber 1010 and the start of the subsequent work, asterilizing process for sterilizing the inside of the work chamber 1010and the flow channels, which have been used in the previous work, isperformed. The sterilizing process includes a pretreatment step, asterilizing step, and a substitution step.

In the pretreatment step, hydrogen peroxide gas is supplied into thework chamber 1010 from the sterilizing substance supply unit 1030 suchthat the concentration of the hydrogen peroxide gas within the workchamber 1010 is maintained at a concentration, which is greater than orequal to the concentration necessary for the sterilization within thework chamber 1010. In the pretreatment step, when the concentration ofthe hydrogen peroxide gas within the work chamber 1010 becomes greaterthan or equal to a predetermined concentration, the sterilizing step isstarted.

In the sterilizing step, sterilization is performed by circulation ofthe hydrogen peroxide gas in which the hydrogen peroxide gas is sentinto the work camber 1010 from the sterilizing substance supply unit1030 and again returns to the sterilizing substance supply unit 1030through the three-way valve 1052. More specifically, in the sterilizingstep, the three-way valve 1044 is switched such that only the directionfrom the channel 1080 toward the channel 1072 is in an open state andthe direction from the channel 1070 toward the channel 1072 is in aclosed state. On the other hand, the three-way valve 1052 is switchedsuch that only the direction from the channel 1076 toward the channel1078 is in an open state and the direction from the channel 1076 towardthe channel 1082 is in a closed state. Thereby, a gas flow channel isformed within the isolator 1100, in which the gas, which has been sentfrom the sterilizing substance sending unit 1036, enters the workchamber 1010 through the three-way valve 1044 and returns to thesterilizing substance sending unit 1036 through the three-way valve1052, thus the hydrogen peroxide gas circulating within the isolator1100.

In the substitution step, the air, which has been taken in through theintake vent 1042, is substituted for the gas within the work chamber1010 by supplying the air into the work chamber 1010 to extrude the gaswithin the work chamber 1010. More specifically, in the substitutionstep, the controller 1090 switches the three-way valve 1044 such thatonly the direction from the intake vent 1042 toward the work chamber1010 is in an open state, and switches the three-way valve 1052 suchthat only the direction from the work chamber 1010 toward the dischargevent 1058 is in an open state. Further, the controller 1090 turns on thefan 1046. Thereby, a gas flow channel is formed within the isolator1100, in which the air that has been taken in from the intake vent 1042is sent into the work chamber 1010 through the channel 1070 and the HEPAfilter 1020 and is discharged from the discharge vent 1058 through thework chamber 1010 and the HEPA filter 1022. As a result, the air issubstituted for the gas in the work chamber 1010 and the hydrogenperoxide gas within the work chamber 1010 is removed from the workchamber 1010.

In this case, the outflow of the hydrogen peroxide gas from thedischarge vent 1058 to the outside of the isolator 1100 can be reducedby the hydrogen peroxide gas, which has been extruded from the workchamber 1010, being subjected to the reduction process by thesterilizing substance reduction process unit 1054. In this case, thecontroller 1090 controls the discharge amount from the fan 1046 based ona concentration measurement result by the concentration measurement unit1056. Also, in the substitution step, the hydrogen peroxide gas, whichremains within areas in the isolator 1100 other than the work chamber1010, for example, the gas supply unit 1040, and the hydrogen peroxidethat is adsorbed in the HEPA filters 1020 and 1022 in the flow channel,which have been used in the previous work, are removed.

In the substitution step, the subsequent work can be started when theconcentration of the hydrogen peroxide gas within the work chamber 1010is smaller than or equal to a predetermined concentration. Theconcentration of the hydrogen peroxide gas at which the subsequent workcan be started means the concentration at which the biomaterial, whichwill be used in the subsequent work, is not affected to the extent thatcannot be neglected for the work. The concentration is, for example,smaller than or equal to 1 ppm (TWA: Time Weighted Average) that isspecified by ACGIH (American Conference of Government IndustrialHygienists). Alternatively, it may be possible that the time for whichthe concentration of the hydrogen peroxide gas within the work chamber1010 becomes smaller than or equal to a predetermined concentration isexperimentally determined and the subsequent work is to be started afterthe determined time has passed.

(Control of Discharge Amount in Substitution Step)

Subsequently, changes in the concentration of the hydrogen peroxide gasand in the discharge amount in the substitution step will be described.FIG. 8 is a schematic graph illustrating the discharge control accordingto Embodiment 2. The upper curve, the middle curve, and the lower curverespectively illustrate the concentration of the hydrogen peroxide gas,the differential component as the rate of change in the concentration,and the successive change in the discharge amount in the substitutionstep in the isolator 1100 according to Embodiment 2.

As illustrated by the lower curve in FIG. 8, the concentration of thehydrogen peroxide gas is measured by the concentration measurement unit1056, which is provided on the gas flow downstream side of thesterilizing substance reduction process unit 1054. The discharge amountfrom the gas discharge unit 1050 is controlled by increasing/reducingthe rotational speed of the fan 1046 in accordance with an order fromthe controller 1090 based on the aforementioned measured concentration,namely, is controlled in the following way such that the acceptabledischarge concentration does not exceed a predetermined threshold value.After the start of the discharge (I), the discharge amount is graduallyincreased by increasing the rotational speed of the fan 1046.Subsequently, after the concentration of the hydrogen peroxide gas inthe discharge gas has reached a predetermined determinationconcentration A (III), the rotational speed of the fan 1046 ismaintained within a predetermined range, thereby the discharge amount ismaintained within a predetermined range, as illustrated by the uppercurve in FIG. 8 (IV). As illustrated by the lower curve in FIG. 8, afterthe concentration of the hydrogen peroxide gas in the discharge gas hasreached the maximum at the time Ta, the discharge is further continued.As illustrated by the middle curve in FIG. 8, after it is confirmed thatthe differential component (reduction rate) of the concentration of thehydrogen peroxide gas has exceeded a predetermined threshold value (V)at the time Tb, the discharge amount is gradually increased by againincreasing the rotational speed of the fan 1046, as illustrated by theupper curve in FIG. 8 (VI). Further, as illustrated by the lower curvein FIG. 8, after the concentration of the hydrogen peroxide gas in thedischarge gas has been reduced to the predetermined determinationconcentration A (VII), the discharge is continued at the maximumdischarge amount until the discharge ends, as illustrated by the uppercurve in FIG. 8 (VIII). The acceptable discharge concentration may beexperimentally determined. It is desirable that the predetermineddetermination concentration A is approximately 40% of the acceptabledischarge concentration, but may be experimentally determined. Thedifferential component of the reduction rate in the concentration of thehydrogen peroxide gas is usually set to a certain negative value as thethreshold value, but may be experimentally determined without beinglimited thereto. Herein, when the discharge amount has reached themaximum output as illustrated by the upper curve in FIG. 8, and when theconcentration of the hydrogen peroxide gas cannot be measured becausethe concentration thereof is below the detection limit of theconcentration measurement unit as illustrated by the lower curve in FIG.8, the discharge is ended by reducing the rotational speed of the fan1046 with the controller 1090. After the concentration thereof hasreached the aforementioned detection limit, the discharge may be endedfurther after X/Y×5 to X/Y×10 sec (where X (m³) is the volume of thework chamber 1010 and Y (m³/sec) is the discharge capability of the fan1046), namely, further after the time for which the gas within the workchamber 1010 is replaced 5 to 10 times has passed.

(Dealing with Performance Deterioration of Sterilizing SubstanceReduction Process Unit)

FIG. 9 is a schematic graph illustrating the relationship between thenumber of the sterilizing process executions and the sterilizing processtime, and illustrating the capability determination of the sterilizingsubstance reduction process unit 1054 according to Embodiment 2.

The measuring unit 1092 measures the time (process time) between thestart and the end of the sterilizing process, that is, the time forwhich a certain time has passed after the concentration of the hydrogenperoxide gas has reached the detection limit of the concentrationmeasurement unit 1056. The recording unit 1094 records the measurementresult in association with the number of the sterilizing processexecutions. The graph (a) in FIG. 9 is made by plotting each sterilizingprocess time (vertical axis), which is obtained herein, relative to thenumber of the sterilizing process executions (horizontal axis). Herein,the controller 1090 determines whether the process time, which has beenmeasured by the measurement unit 1092 and recorded by the recording unit1094, exceeds a predetermined threshold value (b). When the process timeexceeds the threshold value, the controller 1090 communicates that theperformance of the sterilizing substance reduction process unit 1054 hasbeen deteriorated. Thereby, the process unit can be replaced at anappropriate time, and hence the concentration of the hydrogen peroxidegas can be reduced by using the sterilizing substance reduction processunit 1054, the performance of which is always greater than or equal to apredetermined level. The threshold value (b) of the time necessary forthe sterilizing process may be experimentally determined. In addition,the equipment for automatically replacing the sterilizing substancereduction process unit 1054, the performance of which has beendeteriorated, may be further provided, not only communicating that theperformance of the sterilizing substance reduction process unit 1054 hasbeen deteriorated.

In a conventional isolator, the concentration of the hydrogen peroxidegas within a work chamber is rapidly decreased immediately after thestart of a substitution step; however, a reduction rate of theconcentration thereof is significantly decreased. This is becauseefficient discharge cannot be performed in the second half of thesubstitution step in which the concentration of the hydrogen peroxidegas within the isolator becomes is low, since the discharge is performedat a constant discharge amount. Accordingly, the substitution step takesa long time as a result, thereby taking a long time before the workchamber is in a state if being able to be used. On the other hand, inthe isolator 1100 according to Embodiment 2, which is illustrated inFIG. 6, the discharge amount is gradually increased in the substitutionstep, and after the concentration of the hydrogen peroxide gas withinthe work chamber 1010 has reached a predetermined concentration, thedischarge amount is maintained within a predetermined range, in thesubstitution step. And, after it is confirmed that the reduction rate ofthe concentration of the hydrogen peroxide has reached a predeterminedthreshold value, the discharge amount is again gradually increased.Thereby, because the discharge of the hydrogen peroxide into the air,the hydrogen peroxide not being degraded, can be suppressed to theminimum in the first half of the substitution step, the safety of aworker can be secured and efficient discharge can be performed. Further,in the second half of the substitution step, the discharge can beefficiently performed when the concentration of the hydrogen peroxidegas that is being discharged is low because of the control of thedischarge amount according to the present embodiment, although, in aconventional isolator, the discharge cannot be efficiently performedbecause the hydrogen peroxide gas is discharged at a constant dischargeamount. Because of the control of the discharge amount, the timenecessary for the substitution step can be shortened when performing asterilizing process between the previous work and the subsequent workand the isolator 1100 can be set to the state in an earlier time wherethe subsequent work can be started.

Further, the aforementioned safety from the discharge gas can be moresurely secured and the sterilizing time can be more surely shortened bycommunicating that the performance of the sterilizing substancereduction process unit 1054 has been deteriorated based on themeasurement result by the measurement unit 1092.

Embodiment 3

Embodiment 3 is different from Embodiment 2 in the point that thedischarge amount is controlled by feedback. Because the structure of theisolator 1100 other than that and the operations in the sterilizingprocess, etc., are the same as in Embodiment 2, the descriptions will bemade with reference to like drawings and be appropriately omitted.

FIG. 10 is a schematic graph illustrating discharge control according toEmbodiment 3. Specifically, in the substitution step, in which feedbackis performed, in the isolator 100, the successive changes in theconcentration of the hydrogen peroxide gas and the discharge amount areillustrated.

The concentration of the hydrogen peroxide gas is measured by theconcentration measurement unit 1056, which is provided on the gas flowdownstream side of the gas discharge unit 1050 (see the lower curve inFIG. 10). The discharge amount of the gas discharge unit 1050 iscontrolled by increasing/reducing the rotational speed of the fan 1046in accordance with an order from the controller 1090 based on themeasurement result.

As illustrated by the upper curve in FIG. 10, the discharge amount is atfirst gradually increased by increasing the rotational speed of the fan1046 after the start of the discharge (I). Subsequently, as illustratedby the lower curve in FIG. 10, the discharge amount is controlled byfeedback by increasing/reducing the rotational speed after theconcentration of the hydrogen peroxide gas has reached a predetermineddetermination concentration B (II). Herein, as illustrated by the uppercurve in FIG. 10, the discharge amount is controlled byincreasing/reducing the rotational speed of the fan 1046 in accordancewith up/down of the concentration of the hydrogen peroxide gas, whichhas been measured by the concentration measurement unit 1056 (III).

That is, when the concentration of the hydrogen peroxide gas exceeds thepredetermined determination concentration B, the rotational sped of thefan 1046 is reduced such that the discharge amount is reduced. On theother hand, when the concentration thereof becomes below thepredetermined determination concentration B, the rotational speed of thefan 1046 is increased such that the discharge amount is increased.Thereby, the concentration of the hydrogen peroxide gas in the dischargegas is maintained within a predetermined range as illustrated by thelower curve in FIG. 10. Hereinafter, as illustrated by the upper curvein FIG. 10, the discharge amount is gradually increased while thedischarge amount is slightly being increased/reduced such that thedischarge amount is set to the maximum output, which is maintained (IV).As illustrated by the upper curve in FIG. 10, after the concentrationthereof has reached the detection limit of the concentration measurementunit 1056, the discharge is further continued at the maximum dischargeamount (V), and then the discharge is ended (VI). It is desirable thatthe predetermined determination concentration B is approximately 50% ofthe acceptable discharge concentration, but may be experimentallydetermined. In addition, the determination concentration B is not acertain value but a certain range in which the upper limit and the lowerlimit are specified. In this case, the discharge amount may becontrolled so as to be increased when the concentration of the hydrogenperoxide gas in the discharge gas exceeds the upper limit value and tobe reduced when the concentration thereof becomes below the lower limitvalue. In the present embodiment, similar effects as in Embodiment 2 canbe obtained.

Embodiment 4

Embodiment 4 is different from Embodiment 2 in the point that anotherconcentration measurement unit 1060 (see FIG. 11), which is used formeasuring the concentration of the hydrogen peroxide gas, is furtherprovided on the gas flow upstream side of the sterilizing substancereduction process unit 1054. Because the structure of the isolator 1300other than that and the operations for the sterilizing process are thesame as those in Embodiments 2 and 3, descriptions will be made by usinglike symbols and be appropriately omitted.

FIG. 11 is a schematic view illustrating the structure of an isolatoraccording to Embodiment 4. FIG. 12 is a schematic graph illustratingdischarge control according to Embodiment 4, that is, successive changesin the concentration of the hydrogen peroxide gas and in the dischargeamount in the substitution step. In FIG. 12, three patterns of theconcentration I (high concentration), the concentration II (middleconcentration), and the concentration III (low concentration) have beenillustrated. FIG. 13 is a schematic graph in which the detection limitregion C of the concentration of the hydrogen peroxide gas in FIG. 12 isenlarged. M illustrates the successive change in the concentration ofthe hydrogen peroxide gas, which has been measured by using theconcentration measurement unit 1056 on the gas flow downstream side ofthe sterilizing substance reduction process unit 1054. On the otherhand, N illustrates the successive change in the concentration of thehydrogen peroxide gas, which has been measured by another concentrationmeasurement unit 1060 provided on the gas flow upstream side of thesterilizing substance reduction process unit 1054.

As illustrated in FIG. 13, after the measured value (M) by theconcentration measurement unit 1056, which is provided on the gas flowdownstream side of the sterilizing substance reduction process unit1054, has reached the detection limit at the time T1, the concentrationthereof is continuously measured by using the concentration measurementunit 1060, which is provided on the gas flow upstream side of thesterilizing substance reduction process unit 1054, before the measuredvalue by the concentration measurement unit 1060 reaches the detectionlimit at the time T2, thereafter ending the discharge. By measuring,based on a measurement result by the concentration measurement unit1060, the concentration of the hydrogen peroxide gas on the gas flowdownstream side of the sterilizing substance reduction process unit 1054after a measured value has reached the detection limit of concentrationmeasurement unit 1056, a similar effect as in the case where thedetection limit of the concentration measurement unit 1056 is loweredcan be obtained. Alternatively, only the concentration measurement unit1060 may be provided without the concentration measurement unit 1056,which is provided on gas flow downstream side, being provided. In thiscase, the isolator 1100 may be controlled by the controller 1090 basedon a measurement result by the concentration measurement unit 1060 so asto exhibit a similar effect as in Embodiments 2 and 3.

The present invention shall not be limited to anyone of theaforementioned Embodiments 1 to 4, but various modifications such asdesign modification could be made based on the knowledge of a skilledperson. Such modifications could be also within the scope of the presentinvention.

For example, the isolator 1100 according to each of the aforementionedembodiments may be provided with a non-illustrated heater for heatingthe HEPA filter 1020 as a heating means. According to the heater, thehydrogen peroxide, which is adsorbed in the HEPA filter 1020, can bepeeled off more easily. In addition, when the hydrogen peroxide isadsorbed in the HEPA filter 1020 in a solution state, it can beprevented that heat is consumed as the vaporization heat when thehydrogen peroxide in a solution state is vaporized, and hence thetemperature is decreased and the vaporization of the hydrogen peroxideis suppressed. It may be designed that ON/OFF of the heater and theheating amount are controlled by the controller. It is desirable thatthe heating amount for the HEPA filter 1020 by the heater is to theextent in which a change in the temperature in the work chamber 1010 canbe suppressed to, for example, 5° C. or less. The heating of the HEPAfilter 1020 by the heater is performed, for example, on the HEPA filterthat has been used in the previous work after the gas flow channel hasbeen switched to the flow channel, which has not been used in theprevious work, in the substitution step.

Although, in the aforementioned Embodiments 2 through 4, the HEPAfilters 1020 and 1022 are provided on the side surface of the workchamber 1010, these filters may be provided at positions remote from thework chamber 1010.

In the aforementioned Embodiments 2 through 4, the fan 1046, which is anintake fan, is only used and the fan is designed to have the function asa discharge fan as well. However, the fan shall not be limited to anintake fan, but may be a discharge fan. Alternatively, both an intakefan and a discharge fan may be provided. In the latter case, thedischarge amount of the intake fan may be controlled by the controller1090 such that the discharge amount thereof is almost the same as thatof the discharge fan.

Although, in the aforementioned Embodiments 2 through 4, a pass box, athree-way valve for controlling the air in the pass box, and a fan arenot provided, an isolator that is provided with these components may bepossible. Herein, the pass box means the equipment that is provided onthe wall surface of a work chamber and by which entrance and exit ofdust, etc., can be prevented when tools or goods are transferred betweenan anterior chamber and a work chamber, thereby entrance of dust intothe work chamber can be suppressed to the minimum.

In the aforementioned Embodiments 2 through 4, a plurality of valves maybe used such that flow channels can be switched or a three-way valve maynot be used, as long as similar effects as in these Embodiments can beexhibited.

What is claimed is:
 1. An isolator comprising: a work chamber forperforming a work in sterile environment; a gas supply unit configuredto supply a gas into the work chamber; a gas discharge unit configuredto discharge the gas from the work chamber; a sterilizing substancesupply unit configured to supply a sterilizing substance into the workchamber; a fan provided in the gas supply unit or the gas discharge unitand configured to control an amount of discharging the gas from the workchamber per unit time; a reduction process unit configured to reduce theconcentration of the sterilizing substance contained in the gasdischarged from the work chamber; and a controller connected to the fanand configured to start discharging the gas containing the sterilizingsubstance from the work chamber by the gas discharge unit aftersterilizing an inside of the work chamber by supplying the sterilizingsubstance, and to enter the gas containing the sterilizing substance tothe reduction process unit, wherein the controller controls the fan suchthat a first average amount of discharging the gas per unit time from astart of the discharge of the gas containing the sterilizing substanceto a predetermined time is smaller than a second average amount ofdischarging the gas per unit time from the predetermined time to an endof the discharge of the gas containing the sterilizing substance.
 2. Theisolator according to claim 1, wherein the controller includes, a firstcontrol in which the amount of the discharging the gas per unit time ismaintained within a first range before the predetermined time, and asecond control in which the amount of the discharging the gas per unittime is maintained within a second range after the predetermined time,the first range is smaller than the second range.
 3. The isolatoraccording to claim 1, wherein the controller controls the fan such thatan amount of discharging the gas per unit time is gradually increasedfrom the start of the discharge of the gas containing the sterilizingsubstance to a first time, maintained within a first range from thefirst time to a second time, and gradually increased from the secondtime to a third time.
 4. The isolator according to claim 3, wherein thecontroller controls the fan such that the amount of the discharging thegas per unit time is maintained within a second range from the thirdtime to a fourth time, the first range is smaller than the second range.5. The isolator according to claim 4, wherein the fourth time is an endof the discharge of the gas containing the sterilizing substance.
 6. Theisolator according to claim 1, wherein the controller controls the fansuch that a amount of discharging the gas per unit time is nonlinearlyincreased from the start of the discharge of the gas containing thesterilizing substance to an end of the discharge of the gas containingthe sterilizing substance.
 7. The isolator according to claim 1, whereinthe controller controls the fan such that a amount of discharging thegas per unit time is nonlinearly increased from the start of thedischarge of the gas containing the sterilizing substance to a firsttime, maintained within a first range from the first time to a secondtime, and nonlinearly increased from the second time to a third time. 8.The isolator according to claim 7, wherein the controller controls thefan such that the amount of the discharging the gas per unit time ismaintained within a second range from the third time to a fourth time,the first range is smaller than the second range.
 9. The isolatoraccording to claim 8, wherein the fourth time is an end of the dischargeof the gas containing the sterilizing substance.
 10. The isolatoraccording to claim 1, wherein the controller includes, a first controlin which the controller controls the fan such that an amount ofdischarging the gas per unit time is increased from the start of thedischarge of the gas containing the sterilizing substance to a firsttime, maintained within a first range from the first time to a secondtime, and increased from the second time to an end of the discharge ofthe gas containing the sterilizing substance, and a second control inwhich the controller controls the fan such that the amount ofdischarging the gas per unit time is increased from the start of thedischarge of the gas containing the sterilizing substance to a thirdtime, maintained within a second range from the third time to a fourthtime, and increased from the fourth time to the end of the discharge ofthe gas containing the sterilizing substance, the first range is smallerthan the second range.
 11. The isolator according to claim 10, whereinthe second time is substantially equal to the fourth time.
 12. Theisolator according to claim 10, wherein the first time is substantiallyequal to the third time.
 13. The isolator according to claim 12, whereinthe first time is substantially equal to the third time.
 14. Theisolator according to claim 10, wherein the controller selects the firstor second controls based on a concentration of the sterilizing substancein the gas discharged from the work chamber.
 15. The isolator accordingto claim 1, wherein the controller further includes a third control inwhich the controller controls the fan such that the amount ofdischarging the gas per unit time is increased from the start of thedischarge of the gas containing the sterilizing substance to a fifthtime, maintained within a third range from the fifth time to a sixthtime, and increased from the sixth time to the end of the discharge ofthe gas containing the sterilizing substance, the third second issmaller than the third range.
 16. The isolator according to claim 15,wherein the second, fourth and sixth times are substantially equal. 17.The isolator according to claim 15, wherein the first, third and fifthtimes are substantially equal.
 18. The isolator according to claim 17,wherein the first, third and fifth times are substantially equal. 19.The isolator according to claim 15, wherein the controller selects thefirst, second or third controls based on a concentration of thesterilizing substance in the gas discharged from the work chamber.